MEDICAL MONDAYS: News Notes
Dr. Richard Parrish
Dr. Himalaya Lele
MIDDLE TN MEDICAL CENTER
TOPIC: Lung Cancer Awareness
Monday, October 11, 2010
LUNG CANCER Statistics: how common?
Lung cancer is responsible for the most cancer deaths in both men and women throughout the world. The American Cancer Society estimates that 173,770 new cases of lung cancer in the U.S. will be diagnosed and 160,440 deaths due to lung cancer will occur in 2004.
Lung cancer was not common prior to the 1930s but increased dramatically over the following decades as tobacco smoking increased. In many developing countries, the incidence of lung cancer is beginning to fall following public education about the dangers of cigarette smoking and effective smoking cessation programs. Nevertheless, lung cancer remains the most common form of cancer in men worldwide and the fifth most common form of cancer in women.
Lung cancer has also surpassed breast cancer in causing the most cancer-related deaths in women in the United States.
RISK FACTORS FOR LUNG CANCER
DIAGNOSING LUNG CANCER
Your doctor may suspect lung cancer if a routine physical exam reveals:
Some lung cancers produce abnormally high blood levels of certain hormones or substances such as calcium. If a person shows such evidence and no other cause is apparent, a doctor should consider lung cancer.
Lung cancer, which originates in the lungs, can also spread to other parts of the body, such as distant bones, the liver, adrenal glands, or the brain. It may be first discovered in a distant location, but is still called lung cancer if there is evidence it started there.
Once lung cancer begins to cause symptoms, it is usually visible on an X-ray. Occasionally, lung cancer that has not yet begun to cause symptoms is spotted on a chest X-ray taken for another purpose. A CT scan of the chest may be ordered for a more detailed exam.
Though exams of mucus or lung fluid may reveal fully developed cancer cells, diagnosis of lung cancer is usually confirmed through a lung biopsy. With the patient lightly anesthetized, the doctor guides a thin, lighted tube through the nose and down the air passages to the site of the tumor, where a tiny tissue sample can be removed. This is called a bronchoscopy and the scope is called a bronchoscope. This is useful for tumors near the center of the lung.
If the biopsy confirms lung cancer, other tests will determine the type of cancer and how far it has spread. Nearby lymph nodes can be tested for cancer cells with a procedure called a mediastinoscopy, while imaging techniques such as CT scans, PET scans, bone scans, and either an MRI or a CT scan of the brain can detect cancer elsewhere in the body.
If fluid is present in the lining of the lung, removal of the fluid with a needle (called a thoracentesis) may help diagnose cancer as well as improve breathing symptoms. If the fluid tests negative for cancer cells -- which occurs about 60% of the time -- then a procedure known as a video-assisted thoracoscopic surgery (or VATS) may be performed to examine the lining of the lung for tumors.
Because saliva, mucus, and chest X-rays have not proved particularly effective in detecting small tumors characteristic of early lung cancer, annual chest X-rays for lung cancer screening are not recommended by the American Cancer Society, the National Cancer Institute, or the American College of Radiology.
Screening CT scan clinical trials have been performed and some are completed. In one study, over 31,000 people were screened with CT scans and 484 -- or 1.5% -- were found to have lung cancer. Other studies, however, have shown no reduction in lung cancer deaths with CT scanning. Other clinical trials are ongoing.
One of the problems with CT scan screening is the increased risk of radiation exposure and subsequent development of radiation related cancers.
TYPES OF LUNG CANCER
Lung cancers, also known as bronchogenic carcinomas ("carcinoma" is another term for cancer), are broadly classified into two types: small cell lung cancers (SCLC) and non-small cell lung cancers (NSCLC). This classification is based upon the microscopic appearance of the tumor cells themselves. These two types of cancers grow and spread in different ways, so a distinction between these two types is important.
SCLC comprise about 20% of lung cancers and are the most aggressive and rapidly growing of all lung cancers. SCLC are strongly related to cigarette smoking with only 1% of these tumors occurring in non-smokers. SCLC metastasize rapidly to many sites within the body and are most often discovered after they have spread extensively. Referring to a specific cell type often seen in SCLC, these cancers are sometimes called oat cell carcinomas.
NSCLC are the most common lung cancers, accounting for about 80% of all lung cancers. NSCLC has three main types that are named based upon the type of cells found in the tumor. They are:
Other types of cancers can arise in the lung; these types are much less common than NSCLC and SCLC and together comprise only 5-10% of lung cancers:
As discussed previously, metastastatic cancers from other primary tumors in the body are often found in the lung. Tumors from anywhere in the body may spread to the lungs either through the bloodstream, through the lymphatic system, or directly from nearby organs. Metastatic tumors are most often multiple, scattered throughout the lung and concentrated in the peripheral rather than central areas of the organ.
LUNG CANCER TREATMENTS
Surgery is the preferred treatment for patients with early stage NSCLC. Unfortunately, 60-80% of all patients who have advanced or metastatic disease are not suitable for surgery.
Surgery is not widely used in SCLC. Because SCLC spreads widely and rapidly through the body, removing it all by surgery is usually impossible.
An operation for lung cancer is major surgery. Many people experience pain, weakness, fatigue, and shortness of breath after surgery. Most have problems moving around, coughing, and breathing deeply. The recovery period can be several weeks or even months.
Chemotherapy uses powerful medications to kill cancer cells. Chemotherapy is the most effective therapy for small cell lung cancer. It can help control the growth and spread of the cancer, but it cures lung cancer in only a small number of people. Chemotherapy also may be used to treat more advanced stages (stages III and IV) of non-small cell lung cancer.
Chemotherapy is called a systemic treatment because the medicines enter your bloodstream, travel through your body, and kill cancer cells both inside and outside the lung area. Some chemotherapy drugs are taken by mouth (orally), while others are injected into a vein (intravenous, or IV).
Extensive research and clinical trials have studied the different chemotherapy medicines used to treat lung cancer. Some medicines are used for most people with lung cancer. Some are used in combination with others to be more effective. Some may be used before surgery or after surgery. Your oncologist will discuss and recommend chemotherapy treatment specific to your condition.
Radiation therapy is the use of high-energy X-rays to kill cancer cells and shrink tumors. Radiation may come from a machine outside the body (external radiation therapy) or from putting materials that produce radiation (radioisotopes) through thin plastic tubes into the area where the cancer cells are found (internal radiation therapy, also called brachytherapy). Radiation therapy is often used in combination with surgery or chemotherapy or both.
Radiation following surgery for stages II or III non-small cell lung cancer may reduce the risk of cancer recurrence in the chest, but long-term survival rates are not significantly improved because cancer may have already spread to other areas of the body.3
Photodynamic therapy (PDT) uses laser light and a special light-activated substance (Photofrin) to kill cancer cells. It is approved for palliative treatment to destroy tumors that block the airway but it does not cure the lung cancer. Few lung cancers are treated with this therapy. Surgery is still the standard treatment for early-stage lung cancer.
In clinical trials, PDT appears to help relieve coughing, shortness of breath, and coughing up bloody mucus. Additional research is being done.
What to think about
Radiation may cause side effects.
Radiation therapy may be used to prevent small cell lung cancer from growing in your brain. This is called prophylactic cranial irradiation (PCI). PCI can improve survival for people with limited-stage small cell lung cancer whose cancer is in remission from treatment with chemotherapy and with or without radiation to the chest.23
Occasionally, radiation therapy may be given during your surgery. In this procedure, radiation is focused directly on the tumor during surgery and affects as little healthy tissue as possible.
Radiation therapy also may be used as palliative care to:
Other Treatment Choices
Oxygen therapy may relieve your shortness of breath. It is usually used at the end stage of the disease. Some people who have pulmonary conditions, such as chronic obstructive pulmonary disease (COPD), may use oxygen as regular therapy.
Pleurodesis is used to prevent fluid buildup around your lungs. Pleurodesis is a procedure that is intended to cause inflammation of the lining around your lungs. The irritated tissue reacts by producing scar tissue, which causes the two layers of the lung lining to stick together. This removes the space where fluid can build up around your lungs. Pleurodesis is commonly used to treat fluid buildup around your lung that returns after repeated thoracentesis.
In addition to conventional medical treatment, you may wish to try complementary therapies, such as:
Before you try any of these therapies, discuss their possible benefits and side effects with your doctor. Let him or her know if you are already using any such therapies. For more information, see the topic Complementary Medicine.
What To Think About
The combination of conventional medical treatment and complementary medicine is an approach that is sometimes called integrative medicine, in which conventional and complementary therapies are used together for the best outcome.